Field of the Invention
The present invention relates to a tire having a rubber portion formed from ribbon rubber which is spirally wound along a tire-circumferential direction.
Description of the Related Art
As a conventional tire, there is known one having a rubber portion formed from ribbon rubber which is spirally wound along a tire-circumferential direction (e.g., JP-A-2006-69130, JP-2009-119824). Specifically, an unvulcanized tire having a rubber portion formed by spirally winding an unvulcanized ribbon rubber is vulcanized, thereby forming a vulcanized tire.
Here, depending upon a winding manner of unvulcanized ribbon rubber, a rubber-insufficient area (area where rubber does not exist, or areas where rubber is insufficient) is generated in ends of the rubber portion in the tire-width direction in some cases. In such a case, due to the rubber-insufficient area, a vulcanized tire in which air is mixed into the ends of the rubber portion in the tire-width direction is prone to be formed.